Pligg can be used to create website which allows users to submit their links. Other users can vote for the links. If a particular link receives more than certain number of votes then those links can be promoted.

Even it can be used to create community websites and groups.

What is the support for Search Engine Optimization (SEO) ?

Pligg has a nice support for SEO. You can customize how the URLs are built. It can be either a query parameter or it can be a direct url. Other than this it also has an option to specify keywords and description from admin section. Even you can specify different keywords and description for different categories.

Can I customize Pligg ? How to Customize Pligg ?

Yes. You can easily customize pligg. Pligg is written in PHP and MySQL. Anyone who knows little bit of PHP can customize it easily. Even there are some good pligg tutorials available on net.

Can I localize Pligg ?

Yes. You can easily localize pligg. It already has support for localization and presently it supports 12 languages.

Does pligg has SPAM issues ?

Actually the answer to this is Yes. But, in the latest version the SPAM problem is solved upto some extent. But there are pligg plugins and akismet plugin in pligg now, which can be used to get rid of spam links, spam stories and spam comments in pligg. Even there are some ways to get rid of spam in pligg like renaming register.php file frequently.